Neem Oil Insecticide: Natural Pesticide For Plants

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Here’s the deal. There are three all-natural pesticide control products we recommend and reach for when pests in the garden become an issue. Those three are:

Aphids on stem - control aphids with neem oil for plantsPin

Plant pests are one of my least favorite subjects to discuss. Using neem oil, a natural pesticide for plants, makes the pest’s subject at least bearable.

It’s not from the fact plant bugs bother me. That is part of growing plants. However, every “grower” handles pests control differently.

  • In the application method
  • “Chemical insecticides” used
  • Timing of control

It’s a matter of preference from my experience in spraying crops with synthetic chemical pesticides for years.

I choose to use the best product for the job (organic pesticide, if possible) with the least amount of damage to the environment and people.

In this article, we will share information on the versatile natural insecticide Neem Oil, its benefits uses on plants, and controlling garden pests.

If you use natural insecticides in your organic gardening pest control program, you are sure to love Neem oil sprays. 

Related: More on What is Neem Oil?

The neem oil concentrate is an all-natural pesticide made from the oil of the neem seed found on the Azadirachta indica tree.

The oil itself is a yellowish/brown color, tastes bitter, and smells a bit like garlic and/or sulfur.

This natural substance has been used for centuries to treat diseases and control home and garden pests.

Today the neem oil extract is used in a wide variety of home, personal care, and garden products.

Look carefully, and you may find neem essential oil as an ingredient in your shampoo, soap, toothpaste, or even cosmetic products.

Why Does Neem Oil Work As A Pesticide?

Some aspects of the efficacy of pure Neem oil remain a mystery. There are a number of effective components in this natural oil, but the most active ingredient is Azadirachtin.

This ingredient is responsible for repelling and/or killing insect pests. Sometimes this component is extracted to make a highly concentrated product.

The leftover ingredients are then clarified to create a product known as clarified hydrophobic Neem oil. [source]

The many different components of the Neem pesticide work in multiple ways. Azadirachtin works as an insect repellant and reduces insect feeding.

Furthermore, it interferes with the insect hormone systems of insects, so they do not mature correctly or lay eggs. This prevents reproduction.

Related: Tips On How Neem Oil Works On Plant Pests?

In addition to negatively impacting insect pests, Azadirachtin also reduces feeding activity in nematodes. There are also other components in Neem oil that interfere with pests’ ability to feed. [source]

Where Does Neem Oil Come From?

Neem trees grow wild and are cultivated in Southeast Asia. Efforts are also being made to cultivate these ornamental trees in other parts of the world, such as Australia, California, and Florida.

Indian farmers have taken advantage of the powerful insecticidal properties of all of the parts of the Neem tree for many centuries.

In addition to distilling the oil, they have also used the neem leaves and branches to repel pests.

Branches can be hung in barns and grain storage facilities to prevent insect attacks.

Organic Neem OIl Spray for Plants

Neem Oil is our FAVORITE natural organic insecticide. Control aphids, mealybugs, plant scale, Japanese Beetles and more. It can also be used as a soil drench.

If you click this link and make a purchase, we earn a commission at no additional cost to you.

Why Is Neem Oil Beneficial In The Garden?

In the 1970s, Neem oil became available in the Western world, and scientists began exploring its properties and the neem oil uses for plants.

They found that the oil, while a powerful deterrent to unwanted insects, has very low toxicity for humans and animals.

Although Neem oil is most useful as a natural insecticide against soft-bodied larval pests, it can also interfere with the feeding activities of bigger, tougher pests such as beetles.


Penn State also suggests using neem oil for the control of Japanese beetle lawn grubs.

It also works by reducing the levels of Ecdysone (an insect hormone). This disrupts the pest’s molting process and prevents larvae from developing into adult insects.

For this reason, you will sometimes see deformed and crippled insect pests limping about after Neem treatment.

Alternately, immature insects may merely fail to mature and die as nymphs or larvae.

Soft-bodied larvae (e.g., aphids) are killed on contact with Neem oil spray.

Related: Using Neem Oil To Kill Aphids

While many adult insects can survive direct contact with the spray, it may interfere with mating activities.

When used as a garden spray or soil drench, Neem oil does not have long-lasting residual effects.

The neem extract degrades reasonably quickly when exposed to both rainfall and sunlight.

Its insect repelling and killing effects are fast acting for soft-bodied pest insects.

The fact it dissipates quickly means it poses little or no risk to beneficial insects, birds, reptiles, and mammals.

Research has determined that Neem oil does not negatively impact beneficial insects and predators such as earwigs, ants, and spiders, but it does quickly decimate unwanted insects in the larval stage (e.g., flower fly larvae).

Moreover, Neem oil is considered a miticide as it kills mites.

Does Neem Oil Work Alone For Pest Control In Gardening?

Neem oil has a limited effect when used alone in the garden for pest management. It is best to use it in combination with multiple other natural pesticides, beneficial insects, and control methods.

It is very effective as the centerpiece of an integrated pest management (IPM) plan.

In IPM, you would combine careful vigilance (watch for the presence of larval pests) with judicious use of:

Remember, it is always better to use natural remedies in a preventative way than to try to use them to treat raging infections.

As a treatment, they can work; however, they are far more effective when used as preventative measures.

Although there are many neem oil uses, don’t expect instant results, especially when using Neem as a drench.

Because it is an oil neem that will need to travel through the plant and affect its vascular system, it could take two or three weeks for results to be apparent.

This is why it is better to use the oil as a preventative than as a treatment.

If you are treating a problem, begin the moment you notice the problem, be patient, and continue treating it in a preventative way even after your plants have recovered.

How To Use Neem Oil On Plants In The Garden?

There are many ways to use organic Neem oil pesticides for plants to achieve the most significant effect.

Because the oil works in several different ways, pests are very unlikely to build up resistance to it. This is especially true when using neem as part of a comprehensive IPM program. [source]

There are several different ways Neem oil can work to control your insect pest population.

Because it is an oil, it can form a coating on an insect’s body and block its breathing.

It also repels a number of insects. In addition to hampering pest insect activity, it also prevents some types of fungal disease from becoming established by stopping spores from being able to take hold, and it inhibits germination.

A very mild, 1% foliar spray solution of Neem oil kills powdery mildew and has been found effective in controlling powdery mildew on phlox, lilacs, and hydrangeas. [source]

As an insecticide, Neem oil is effective against a wide variety of pests as well as fungal, viral, and bacterial infections when used as a spray or as a soil drench.

Neem cakes made from the by-product of cold-presses neem fruit work as an effective pesticide and a good fertilizer.

No matter what sort of problem you are battling, it’s important to understand the challenge and mix up your organic Neem oil solution accordingly.

You will need a stronger solution for bigger, tougher bugs and/or for more established pests or mold, a viral or bacterial infection.

What Problems Can Neem Oil Help With?

Neem oil kills or helps control as a pesticide nearly 200 species of insects, 15 fungi, and allegedly some bacteria and viruses.

Neem even kills caterpillars!

Generally speaking, if you are having a pest, fungus, or bacterial infection problem in your garden, try spraying some Neem oil on it!

Large colony of aphids with Ladybug feeding on themPin

It will probably help, and it won’t hurt.

Does neem oil kill ants? 

Here is a list of the garden pests Neem oil and Neem products are known to help control. 

Related: For more, check out our article What Bugs Does Neem Kill?

Anecdotal evidence also indicates limited success with garden slug and snail control.

The only study was done on the effects of Neem oil on gastropods involving edible tropical snails and indicated the product is not effective against them. [source]

What Are The Guidelines For Mixing Neem Oil Spray?

How to mix neem oil for plants:

When it comes to mixing Neem oil solutions, you may feel a bit daunted because there are not any precise and exacting rules.

You will need to gauge your situation and consider the type of plant you are treating, as well as the type of pest or infection you are attacking.

You’ll need a stronger solution for tougher and more persistent problems.

As with most natural remedies and organic pest control, it is better to set prevention as your goal than eradication.

Establishing diligent habits of inspection and regular spraying with a mild Neem solution is much more effective than attempting to get rid of a massive infestation or infection after the fact.

Generally speaking, if you want to mix up a good, mild, general-purpose preventative garden spray, go with a half-percent or one-percent solution.

If you are dealing with tough or established pests, you may want to mix a stronger two-percent solution.

If you are starting out, begin with the half-percent solution. If it is not effective, you can always add more Neem.

Observe the results of your spraying and adjust your measurements accordingly.

Keep in mind that Neem oil does not kill insects immediately upon contact. You will probably need to spray daily for a week or so to observe the spray’s effect on your plants and your pests.

General Purpose Organic Garden Spray

How to make neem oil spray for plants:

Here’s a basic recipe for a good, general-purpose .5% garden spray.

  • 1 quart of warm water
  • 1 teaspoon of pure, cold-pressed Neem oil
  • 1/3 teaspoon of dish soap or insecticidal soap
  • Spray bottle or spray applicator

If you want a 1% solution, double the amount of Neem oil and insecticidal soap. If you want a 2% solution, quadruple the amounts.

You can do the math to make a big batch of any strength but keep in mind that Neem oil degrades quickly when mixed with water.

Do not mix up more than you can use within a couple of hours of combining the ingredients.

12 Tips For Using Neem Oil Successfully In Your Garden

  1. Always use high-quality organic cold-pressed Neem oil.
  2. Don’t try to mix Neem oil with cold water. Always use warm water with liquid soap or insecticidal soap already mixed in.
  3. If making a big batch, mix up the Neem oil in a small container of warm water and soap first, then add it to the larger container of water.
  4. You can mix up your spray in a separate container and then pour it into the sprayer or mix it in the sprayer.
  5. Shake your mixture periodically as you work to prevent the oil and water from separating.
  6. Use all of your spray solutions within eight hours of mixing.
  7. If you have a solution left over after you finish spraying, use it as a soil drench to get root-knot nematodes and other soil-dwelling pests under control and improve the condition of your soil.
  8. Neem oil can become semi-solid at cool temperatures, so be sure to create your Neem oil mixture indoors or on a warm day. If you are doing all this and your Neem oil remains semi-solid, try adding a little more dish soap or insecticidal soap to help dissolve the oil.
  9. When applying a Neem oil spray, be sure to coat all surfaces of the plant thoroughly. Get the topsides and undersides of leaves, and all stem, stalk, and trunk surfaces. Apply extra in bends and crooks, as pests like to hide in these natural crevices.
  10. If it is very sunny, windy, or if it rains, you will need to reapply your Neem oil solution.
  11. If you are concerned the spray may injure some plants, do a test in a small area before spraying the entire plant. Put a small amount of the solution on a small part of the plant and check back in 24 hours to see if there have been any adverse effects. If not, go ahead and treat the whole plant.
  12. Pure Neem retains its potency much longer if stored at about 40° degrees Fahrenheit in low light and in a dark container.

How Often Can You Use Neem Oil On Plants?

The frequency of spraying varies depending on your intentions, the type of plants you are treating, the kind of pests you are dealing with, and the weather.

Because of all these variables, your powers of observation are critical.

Keep a close eye on your plants so you notice pest and fungal invasions early on.

Begin treatment immediately, using the mildest solution, and then observe to determine the results.

It’s generally a good idea to spray again in two or three days as insurance and keep a close eye on your plants for further signs of problems.

If you are starting out with Neem oil sprays and already have a burgeoning population of pests or heavy mold, bacterial or viral infection, you’ll need to use a 2% concentration.

Be sure to thoroughly drench every part of the plant and the soil all around it. Repeat this treatment weekly (or sooner in case of rain) until the problem clears up.

Continue to monitor closely, apply a preventative half-percent solution, and treat more aggressively with a stronger solution as needed.

If you want to use a half percent solution as an ongoing preventative spray, plan on spraying every couple of weeks. This should help prevent pest and mold problems.

When plants are very young, apply a half percent solution as a foliar spray weekly and as a soil drench every couple of weeks to keep them safe.

The oil will stay effective in the soil for about three weeks. On the leaves, it is only effective for about an hour, but it will kill pests present when you spray.

How And Why You Should Use Neem Oil As A Soil Drench?

When you use Neem oil as a soil drench, it works as a systemic insecticide. The plant roots draw the neem oil up into the plant’s vascular system. [source]

This means the oil is present throughout the plant structure, and harmful insects dining on your plant will consume a dose of Neem oil.

Related: Read our article to learn more about Neem Oil As a Soil Drench.

Using Neem Oil For Insect Control on Houseplants

One of the problems houseplant homeowners face comes with their indoor pest control options. They are limited!

This is why we use 100% Pure Neem Oil to naturally control indoor pests such as:

Neem oil is an excellent SAFE, NATURAL insecticide/pesticide solution for homeowners with pest problems.

We DO NOT recommend spraying any type of insecticide indoors.

If you cannot take your plant(s) outdoors to thoroughly spray them, clean the plant and wipe it down with a mixed neem oil solution.

For more read: [Top Tips] How To Clean Plant Leaves On Houseplants

From Personal Experience

NOTE: I’ve used Neem as a foliage grower and spoken to other foliage, flower, orchid, and bromeliad growers using Neem oil spray as an insecticide in their “pest control” program. 

They are very pleased with the results. Not just from the safety aspect but the control.

How Does Neem Oil Work For Fungus?

You can also use Neem oil in a mild, 1% solution to treat a wide variety of plant fungal diseases and infections, including powdery mildew, rust, sooty mold, black spot, and root rot.

It is very good to use on fruit trees and roses (good for controlling black spots) as both a foliar spray and a soil drench.

Related: Details on Using Neem Oil On Roses and How Neem Oil Helps Control Root Rot.

Since Neem oil is a safe, non-toxic, and non-carcinogenic pest control option, it is an excellent choice for keeping your veggie garden fungus free.

It is especially effective for reducing leaf spot on vegetables such as melons and tomatoes, which are susceptible to fast-spreading fungal infections.

Check out Using Neem Oil for Tomato Blight | Is Neem Oil Safe For Vegetables

One downside to using Neem oil as a fungicide is that the very qualities that make it safe and environmentally friendly also make it very susceptible to environmental degradation.

Remember, in very hot, very sunny, or very rainy conditions, it must be applied more frequently to be effective.

Take care when applying Neem oil to delicate plants, as high concentrations can harm them.

Generally speaking, it is always best to start out with the mildest solution and see how it works. If you need a stronger solution, you can always add more.

foliar spray of neem oil on plants is very effectivePin

How Do You Apply Neem Oil As A Foliar Spray?

Remember that heavy or very strong applications of Neem oil can harm or even kill some delicate plants.

Keep this in mind when spraying young plants. However, I have never personally had any issues.

Before applying Neem oil to a whole plant, test a small area of it. Wait a full day and night and check for plant leaf damage.

If you do not find damage, then you can go ahead and apply the solution.

Don’t apply a Neem oil solution on the day of harvest or when extreme weather conditions are present.

Remember, the oil degrades in heat, wind, direct sunlight, and rain, so wait for a still, pleasant day when no inclement weather is predicted.

Don’t apply the solution to plants that are under stress due to drought conditions or improper watering (either over or under-watering).

If you are planning to water and apply a foliar spray, water several hours before spraying.

Alternatively, you may wish to water one day and spray the next.

Apply the spray carefully, making sure all parts of the plant and plant leaves are coated. Naturally, you should give extra attention to areas where you find any infestation.

The frequency of spraying neem oil also depends on the type of insect you are combating. If it is an insect with a short life cycle that reproduces quickly (e.g., spider mites), spray every couple of days for two or three weeks.

How Can You Use Neem Oil With Horticultural Oil?

Both vegetable and petroleum-based oils are often used as protective sprays for food-producing crops.

For example, dormant oil is frequently applied to fruit trees late in the autumn and during the winter months to reduce the emergence of insect pests in the springtime.

These types of oils usually are not toxic. They work by the physical mechanism of smothering pests, larvae, and eggs as they overwinter.

Because they are entirely toxin-free, horticultural oils have no residual effects.

When you add Neem oil to a horticultural oil, you add an element of targeted toxicity since this oil interferes with insect pests’ ability to attain sexual maturity and reproduce.

Related: Neem Oil vs. Horticultural Oil What Is The Difference?

It can also stop the development of insect eggs upon contact.

If you want to try this combination on your fruit trees, add a tablespoonful of Neem oil to each quart of horticultural oil you use.

Mix the oils thoroughly and spray the trees completely. Focus carefully on knots and forks. Be sure to remove dead branches before winter, as they tend to harbor pests.

Neem Oil Is Also Antimicrobial!

In addition to its insecticidal and anti-fungal properties, Neem oil is also anti-viral and antibacterial.

In India, neem products are used for medicinal, personal care, and cosmetic purposes.

The oil distilled from the neem seeds can be used to make lubricants, soaps, and many other useful products.

Traditionally, twigs from the neem tree were used for tooth cleaning as both brushes and picks.

In India, Neem leaf paste is used in a wide variety of medical treatments. It is valued as a wound dressing in both human and veterinary medicine.

The paste works wonders to treat bacterial skin infections and fungal infections such as ringworm. People in India also enjoy Neem leaf tea as a chickenpox preventative and as a treatment for stomach infections.

These antimicrobial properties are also valuable for use in plants; Neem oil provides broad-spectrum antimicrobial action.

For a potent antifungal and antimicrobial plant oil spray, mix a couple of tablespoons of Neem oil, a teaspoon of dish soap, and a gallon of water (warm) to keep your plants free of botrytis, black spot, scab, blight, mildew, anthracnose, and rust.

How Safe Is Neem Seed Oil?

Neem oil is remarkably benign, but you must use it as directed. Read all the product information before applying.

According to the Environmental Protection Agency (EPA), Neem oil is generally recognized as safe (GRAS). If you are using it on your veggie garden plants, be sure to wash your produce thoroughly (as you would anyway) before eating it. [source]

I would always recommend wearing protective pest control spray clothing and a pesticide respirator when spraying plants. The EPA has no restrictions in place.

Improper use could cause problems. Naturally, you should never drink garden Neem oil (but there are some Neem teas and supplements made specifically for ingestion).

Remember that Neem oil interferes with reproduction in insects, so even though it may seem a bit overly cautious, if you are pregnant or trying to conceive, take care when handling Neem oil.

Generally speaking, Neem oil is not dangerous for beneficial insects such as ladybugs, butterflies, and bees because they don’t chew on plant leaves.

Nonetheless, excessive use of Neem oil may be harmful to bees. Avoid spraying it onto blossoms that bees frequent.

Avoid having Neem oil spray come in direct contact with bees.

Learn more: Does Neem Oil Kill Bees?

NOTE: According to the Safer® brand, “neem oil, when used in smaller quantities, won’t harm medium to large hives or the honey bees, so you can keep your pollinators and plants alive.

Where Can You Buy Neem Oil Spray For Plants?

Most garden centers and big box stores (some grocery stores) carry Organic Neem Oil Insecticide for plants in the same area where you’ll find synthetic pesticides.

Look for Neem Tree products by Safer® Brand or Bonide. However, I order mine from Amazon.Pin

Use 100% Pure Neem Oil products to naturally control:

  • Aphids
  • Scale
  • Mealybugs
  • Mites
  • Thrips
  • Scale insects
  • Powdery mildew

Neem oil spray is an excellent SAFE, NATURAL insecticide/pesticide solution for homeowners with pest problems.

Overall, Neem tree oil is very safe as it is practically non-toxic to people, pets, and all sorts of wildlife, and it is not at all carcinogenic.

Even so, handle Neem with care, and follow all packaging instructions closely.

NOTE: The United Kingdom has banned pesticides containing azadirachtin, the active ingredient in neem oil. [source]

Neem oil is our #1 go-to product for natural pest control and an excellent solution for homeowners.

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